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In this issue:
LCLS Injector Gun: The One-minute Overhaul
Safety Today: New Chemical Labels Service
GLAST Seminar Today
LUSI Project Completes Critical Decision 2 Review

SLAC Today

Tuesday - August 26, 2008

LCLS Injector Gun: The One-minute Overhaul

Physicist Axel Brachmann with the transport chamber that houses the defective cathode from the LCLS injector, removed earlier this month. (Photo by Brad Plummer. Click for larger image.)

The injector for the Linac Coherent Light Source has a shiny new electron source, or cathode, thanks to a recent repair project aimed at correcting a problem that began earlier this summer. After days of detailed planning, replacing the LCLS cathode took only about one minute, according to Axel Brachmann, the injector physicist who led the effort.

"You just have to plan it well, then you do it," Brachmann said of the pit-crew-style changeout.

The injector cathode is a highly polished copper plate used to generate the initial pulse of electrons for the LCLS. The process starts when a short burst of light from a drive laser hits the cathode's shiny surface. Normally, the cathode would produce one electron for every 100,000 photons. But earlier this year during injector commissioning, physicists noticed a drop in the number of electrons coming off the cathode. Attempts to clean the cathode using the drive laser showed promise at first, but after several such attempts it became clear the cathode would have to be replaced. The LCLS collaboration keeps a few spare cathodes on hand for just such an occasion, under vacuum in specially designed transport chambers.  Read more...

(Column - Safety Today)

New Chemical Labels Service

New for you: pre-printed labels for chemical containers. (Photo courtesy of Judy Fulton. Click for larger image.)

If you work with chemicals, you know that unlabeled containers must be assumed to contain something nasty and hazardous. That's why SLAC policy requires labels on all containers. "No problem," you might think, "chemical products come labeled from the supplier." But what if you need to transfer chemicals to smaller or newer containers, or fill a squeeze bottle? Maybe the original label is torn and hard to read. In these cases, you need to place a new or secondary label on the container.

Like the original labels, secondary labels must provide certain information regarding the hazards of the material. To make this easier, the Chemical Management Services program and our chemical management service company, Haas TCM, are providing pre-printed secondary labels for the products that are most-commonly transferred to new containers. These products include isopropyl alcohol, acetone, ethanol and mineral oil.

The labels are waterproof and chemical resistant. They come in two sizes: 4 x 3 inch and 2 x 1 inch. They are pre-printed with the chemical name, National Fire Protection Association hazard rating diamond, part number, body organs possibly affected by the chemical, and the Web page for Material Safety Data Sheet lookup (by part number).

Need a label for your squeeze bottle? Contact Ray Barbara (x8776) with the product part number, the label size and quantity.

SLAC on-site Haas services representative Ray Barbara prints a label. (Click for larger image.)

GLAST Seminar Today

All SLAC staff are invited to attend a scientific seminar on the Gamma-ray Large Area Space Telescope first light results, today at 2:00 p.m. in Panofsky Auditorium. NASA will announce the initial results in a press conference at 11:00 a.m. today. Representing the GLAST collaboration, SLAC scientists Elliott Bloom and Seth Digel will give SLAC staff a closer look at the results, followed by a brief question and answer session.

LUSI Project Completes Critical Decision 2 Review

(Image - X-ray Correlation Spectroscopy instrument diagram)Congratulations to the scientists and engineers of the Linac Coherent Light Source Ultrafast Science Instrumentation project, or LUSI. The team last week successfully completed Department of Energy review for Critical Decision 2, or CD2. This is a huge milestone for the group and for the Linac Coherent Light Source collaboration as a whole, giving the green light for instrument designs and cost estimates.

"I'm sure the LUSI team feels pretty good right now. You’ve earned it," said LCLS director of construction John Galayda during the review closeout session last Thursday.

(Image - X-ray Pump Probe instrument diagram)SLAC Director Persis Drell thanked the DOE review panel and offered her congratulations to the LUSI team. "I'm really proud of how this has come together. The laboratory thanks you for your efforts."

The three day review took place to evaluate the scientific program underlying the LUSI project, as well as the data collection, control and safety systems associated with the instruments.

(Image - Coherent X-ray Imaging instrument diagram)The LUSI project comprises an initial set of three instruments, to be built by 2012, for use with the LCLS: X-ray Correlation Spectroscopy (top image), X-ray Pump Probe (second image), and Coherent X-ray Imaging instruments (third). 

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